In physics, it's common to develop a formula and then stick a constant to explain the unknown. For example, Newton's theory of gravity uses the gravitational constant G on the formula F = G * m_1 * m_2 / r^2, later on Einstein gave a more accurate explanation with the theory of relativity which does not rely on a constant E = m * c^2. Constants provide a good enough explanation of the laws of physics that's useful for centuries.

I was wondering what's the equivalent in social studies? How do researchers deal with the uncertainty of human behaviour?

Edit: Comments made me remember how much I don't understand the theory of relativity, terrible example, sorry for the confusion. I need to rephrase the question but I don't know how.

I am looking for "glue" concepts, things that help connect observations with theory, aka if I calculate m_1 * m_2 / r^2 the result is slightly off but if I account for G, an empirical constant derived from observation, then everything makes sense for the observable universe.

Also, as someone said, I am referring to social studies.